Hello There, Can anyone help me please? I've got 9 off Fire Doors to paint and got some Dulux Primer/Undercoat (quick drying paint). It's that quick, it is dry immediately after applying and really patchy. Using a brush, I can't seem to get a uniform finish. I've prep'd cleaned the door, sanded and de-dusted before starting on the doors. Is there a solution of some kind that I should have used on the door before priming or is that just as it is with this paint and I just sand it again and get on with the second coat. Cheers again.